Atlas Elektronik UK proposes mid-size USVs as naval force multipliers

Uncrewed Surface Vehicles have already proved able to deliver a basic autonomous mine hunting capability for the Royal Navy. Here we look at proposals by AEUK to expand the role of USVs to act as sensor and weapon platforms.

Autonomous boats carrying sensors and effectors is not a new concept but other than in mine warfare roles, the first operational examples have mostly been smaller low-cost/attritable solutions. The emergence of the ‘kamikaze’ one-way attack boats developed by Ukraine and used by the Houthis in the Red Sea are the most high-profile examples of weaponised USVs. The RN is currently trialling an autonomous RIB armed with an automatic weapon. The Iranian navy (or IRGC) probably has gone furthest in developing heavily armed boats of this size, although not yet fully autonomous.

Value proposition

Slightly larger and more sophisticated mid-sized USVs have the potential to enhance or even replace expensive warships for some tasks. A boat approx 10-20m in length with a displacement in the 15-25 tonnes range has the capacity and range to carry quite sophisticated useful distances. The mid-size USV is small enough to be road-transportable or embarked on vessels of large frigate size or above and has sufficient stability to operate in conditions up to sea state 4. This means they are ideal for use in the littorals, for coastal defence or supporting amphibious operations. In some circumstances, they need not even embark in a host vessel but could sail in company with the warship and be used as a mini Surface Action Unit. Alternatively, the USV or multiple USVs could be controlled from a land-based operations centre independent of any warship support or tactical command.

The advantages of autonomy are well rehearsed but in this context includes the ability to take on high-risk missions without risk to life, an affordable way to add mass when hull numbers are lacking and a way of extending the sensor horizon well beyond the surface ship’s own sensors. A mid-size USV used to reduce risk to a £1bn+ warship and its crew or multiplying its effect, would represent very good value. The 15m SEA class workboats produced for the RN by AEUK cost in the £1-2M range, depending on equipment fit and economies of scale which compares favourably with the price of a single high-end missile.

In a navy struggling for sailors, the attraction of autonomous systems are obvious. For the next few years at least, the RN is going to have declining surface combatant numbers and USVs could help offset this lack of mass, being relatively cheap to acquire and quick to manufacture.

Multi-mission

The mid-size USV can carry a wide range of payloads. At the simpler end of the spectrum would be a ‘picket boat’ sent up-threat and equipped with ISR equipment such as EO cameras and a small radar to provide a measure of early warning. Acting as a maritime sentry patrolling harbours or offshore installations, a few boats could provide a 24/7 surveillance capability at a fraction of the cost of crewed craft.

USVs could also carry Electronic Warfare (ESM and CESM) emitters and receivers for both passive electronic intelligence gathering or active jamming and spoofing. A USV with appropriate equipment could be configured to simulate the signature of a warship to act as a decoy, either to cause confusion or decoy missile attacks.

Since Anti-Submarine Warfare is typically a ‘team sport’ the USV is unlikely to be employed to operate alone but carrying towed sonars they could work with frigates or helicopters utilising multi-static sonars. This can dramatically increase the effective search area, the likelihood of detection, location accuracy and extend the coverage of the Recognised Maritime Picture.

Launch and recovery systems have already been designed and developed for mine hunting sonars and it would not be difficult to modify them for ASW use. This is a low-cost way to deter underwater intruders such as Swimmer Delivery Vehicles, UUVs or submarines. A few USVs could effectively maintain an ASW barrier to protect an amphibious area of operations, sanitise sensitive sea areas such as the Firth of Clyde or protect critical undersea infrastructure.

The SEA Class are based on the 11m ARCIMS series of boats, which is a mature design, being MARPOL emissions and IMO navigation-compliant. Five ARCIMS boats are currently in service with the RN for mine sweeping and mine hunting. They are air-transportable and would fit in the Mission Bay of a Type 26 frigate.

Strike craft

At the more ‘fighty’ or kinetic end of the spectrum, USVs could serve as weapons platforms, effectively extending the range of missiles or torpedoes. In this role integration with other sensor and control platforms is especially important as they act as a weapon delivery truck cued by form elesewhere. For coastal and littoral defence the USV is a much cheaper and more persistent option than using helicopters to prosecute underwater targets detected by seabed arrays or other platforms. With the development of advanced UUVs which will add mass to the underwater battle, affordable and agile means to counter this new threat are needed.

If fitted with anti-ship missiles the USVs could be deployed from a surface ship and sent to penetrate area access denial bubbles and much lower risk. With their tiny radar signature, the USV could potentially achieve launching positions much closer to the target than a warship or helicopter could manage without detection. A ‘swarm’ of missile-equipped USVs could also be coordinated to create a saturation attack from multiple axes.

Obstacles

There are still challenges to overcome in making USVs effective weapons and sensor platforms that are safe to operate. The civilian regulatory environment generally requires repeatable, consistent, and predictable behaviours from remotely controlled or autonomous vessels. This is at odds with the need for military systems to sometimes behave unpredictably to maintain tactical advantage.

Moving up the autonomy scale from (level 3) remote human operator to (level 4) full machine operation is a big step. Allowing the USV to make its own decisions based on input from sensors, the mission requirement and the tactical situation will ultimately be most effective but few militaries in the Western world are yet comfortable with this level of independence. There are also maintenance challenges with ensuring all moving parts work extremely reliably in the absence of a sailor who can rectify even simple problems that might render an uncrewed platform ineffective or even lost.

There are also the issues of maintaining secure bandwidth to pass large amounts of data between the USV and C2 node in potentially denied environments. The RN already has already accumulated some knowledge and experience of the issues around Maritime Autonomous Systems but needs to push more aggressively to operationalise promising experimental projects and technology demonstrators.

The ARCIMS and SEA Class boats have already been designed with COLREGS-aware autonomy capability as standard. Other manufacturers could provide USVs but using the British-built AEUK designs as a basis for evolved USVs would make sense. This would provide commonality with the workboats and MCM boats in RN service for logistic support and training. Mid-sized USVs are not a panacea or a replacement for warships and have limited utility for blue water operations but do represent a very affordable force multiplier. With much of the underpinning technology already proven in service, this is an option worth pursuing for overstretched navies with gaps to fill.

All images: AEUK